U.S. patent application number 10/361820 was filed with the patent office on 2004-04-01 for magnetron for microwave ovens.
This patent application is currently assigned to Samsung Electronics Co., Ltd.. Invention is credited to Han, Dae-Sung, Han, Yong-Woon, Jang, Seong-Deog, Kang, Han-Seong, Yeo, Joo-Yong.
Application Number | 20040060933 10/361820 |
Document ID | / |
Family ID | 31973685 |
Filed Date | 2004-04-01 |
United States Patent
Application |
20040060933 |
Kind Code |
A1 |
Han, Yong-Woon ; et
al. |
April 1, 2004 |
Magnetron for microwave ovens
Abstract
A magnetron for microwave ovens including a second insulator
interposed between a connection part and a bottom of a yoke to form
a relatively lengthened insulation distance, or a molded insulating
plate attached to a bottom of the filter box to reduce a distance
between the connection part and a bottom of the filter box. In the
magnetron, an entire height of the magnetron is reduced, so that a
miniaturization of the magnetron can be implemented and a design of
a product including the magnetron, such as a microwave oven, can be
freely carried out, thus allowing an appearance of the product to
be variously designed.
Inventors: |
Han, Yong-Woon; (Kunpo-City,
KR) ; Jang, Seong-Deog; (Suwon-City, KR) ;
Kang, Han-Seong; (Suwon-City, KR) ; Yeo,
Joo-Yong; (Suwon-City, KR) ; Han, Dae-Sung;
(Hwasung-City, KR) |
Correspondence
Address: |
STAAS & HALSEY LLP
SUITE 700
1201 NEW YORK AVENUE, N.W.
WASHINGTON
DC
20005
US
|
Assignee: |
Samsung Electronics Co.,
Ltd.
Suwon-City
KR
|
Family ID: |
31973685 |
Appl. No.: |
10/361820 |
Filed: |
February 11, 2003 |
Current U.S.
Class: |
219/756 |
Current CPC
Class: |
H01J 23/15 20130101;
H01J 25/587 20130101 |
Class at
Publication: |
219/756 |
International
Class: |
H05B 006/64 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 26, 2002 |
KR |
2002-58413 |
Claims
What is claimed is:
1. A magnetron for microwave ovens, comprising: a positive polar
section forming a cavity resonator; a negative polar section
emitting thermions; a yoke accommodating and supporting the
positive polar section; leads extended to an outside through a
bottom of the yoke to be supplied with power by an outside power
source; a connection part connecting the leads with the outside
power source; a filter box accommodating the connection part
therein; a first insulator fixedly supporting the negative polar
section, being positioned between the connection part and the
bottom of the yoke, and having a height to maintain an insulation
distance between the connection part and the bottom of the yoke;
and a second insulator interposed between the connection part and
the bottom of the yoke to form a lengthened insulation distance for
dielectric breakdown in comparison to a distance between the
connection part and the bottom of the yoke.
2. The magnetron as set forth in claim 1, wherein the first
insulator is made of ceramic material.
3. The magnetron as set forth in claim 1, wherein the second
insulator is made of ceramic material.
4. The magnetron as set forth in claim 3, wherein: the first
insulator is provided with at least one circular groove that is
formed in a lower portion of the first insulator to be downwardly
open, and the second insulator is provided with at least one
circular protrusion that is fitted into the at least one circular
groove of the first insulator to lengthen the insulation distance
between the bottom of the yoke and the connection part.
5. The magnetron as set forth in claim 4, wherein the lengthened
insulation distance is more than 16 mm.
6. The magnetron as set forth in claim 4, wherein the second
insulator further comprises: a shield portion that blocks the
connection part from the bottom of the yoke, the yoke being
electrically reactable with the connection part.
7. The magnetron as set forth in claim 6, wherein the shield
portion comprises: a disk integrated with the at least one circular
protrusion; and a mounting protrusion extended from the disk in a
direction of protrusion of the at least one circular protrusion and
fixed to the yoke.
8. The magnetron as set forth in claim 1, further comprising; an
insulating plate attached to a bottom of the filter box to reduce a
distance between the connection part and the bottom of the filter
box.
9. The magnetron as set forth in claim 8, wherein the insulating
plate is made of a material having a high heat resistance.
10. The magnetron as set forth in claim 8, wherein the insulating
plate is made of a material having a high dielectric strength.
11. The magnetron as set forth in claim 8, wherein the insulating
plate is molded.
12. A magnetron for microwave ovens, comprising: a positive polar
section forming a cavity resonator; a negative polar section
emitting thermions; a yoke accommodating and supporting the
positive polar section and determining an amount of magnetic flux;
leads extended to an outside through a bottom of the yoke to be
supplied with power by an outside power source; a connection part
connecting the leads with the outside power source; a filter box
accommodating the connection part therein; and a molded insulating
plate attached to a bottom of the filter box to reduce a distance
between the connection part and the bottom of the filter box.
13. The magnetron as set forth in claim 12, wherein said insulating
plate is made of a material having a high heat resistance.
14. The magnetron as set forth in claim 12, wherein said insulating
plate is made of a material having a high dielectric strength.
15. A magnetron for microwave ovens including a positive polar
section forming a cavity resonator, a negative polar section
emitting thermions, and a yoke accommodating and supporting the
positive polar section, comprising: first and second leads
extending through a bottom of the yoke to be supplied with power by
a power source; a connection part connecting the first and second
leads with the power source; a box accommodating the connection
part therein; a first insulator fixedly supporting the negative
polar section, being positioned between the connection part and the
bottom of the yoke; and a second insulator interposed between the
connection part and the bottom of the yoke such that an insulation
distance for a dielectric breakdown is formed between the first and
second insulators, the first and second insulators are shaped such
that the insulation distance for a dielectric breakdown is greater
than a distance between the bottom of the yoke and the connecting
part.
16. The magnetron as set forth in claim 15, wherein one or both of
the first and second insulators are made of a ceramic material.
17. The magnetron as set forth in claim 15, wherein: the first
insulator is provided with one circular groove thereon; and the
second insulator is provided with one circular protrusion
corresponding to the one circular groove of the first insulator to
lengthen the insulation distance according to a height and a width
of the one circular groove.
18. The magnetron as set forth in claim 17, wherein: the first
insulator is provided with at least one other circular groove
thereon; and the second insulator is provided with at least one
other circular protrusion corresponding to the at least one other
circular groove of the first insulator to further lengthen the
insulation distance according to a height and a width of the at
least one other circular groove.
19. The magnetron as set forth in claim 16, wherein the lengthened
insulation distance is more than 16 mm.
20. The magnetron as set forth in claim 15, wherein the second
insulator further comprises; a shield portion that shields the
connection part from the bottom of the yoke, the yoke being
electrically reactable with the connection part.
21. The magnetron as set forth in claim 17, wherein the shield
portion comprises: a disk with the one circular protrusion; and a
mounting protrusion extended from the disk in a direction of
protrusion of the one circular protrusion and fixed to the
yoke.
22. The magnetron as set forth in claim 1, further comprising; an
insulator attached to and covering a bottom of the box to reduce a
distance between the connection part and the bottom of the box.
23. A magnetron for microwave ovens including a positive polar
section forming a cavity resonator, a negative polar section
emitting thermions, and a yoke accommodating and supporting the
positive polar section and determining an amount of magnetic flux,
comprising: first and second leads extending through a bottom of
the yoke to be supplied with power by a power source; a connection
part connecting the first and second leads with the power source; a
box accommodating the connection part therein; and an insulator
attached to and covering a bottom of the box to reduce a distance
between the connection part and the bottom of the box.
24. The magnetron as set forth in claim 23, wherein the insulator
is made of a high heat resistance material.
25. The magnetron as set forth in claim 23, wherein the insulator
is made of a high dielectric strength material.
26. A magnetron for microwave ovens with a casing, comprising:
first and second leads; and first and second insulators interposed
between and insulating the first and second leads from a bottom of
the casing, the first and second insulators having respective and
corresponding circular grooves and circular protrusions; wherein
the first and second leads are extended through and are insulated
from the casing and are supplied by a high voltage power source
such that a first voltage level is provided across the first and
second leads, the casing being maintained at a second voltage level
with respect to the first lead, and an insulating distance for a
dielectric breakdown is greater than a smallest distance between
the casing and one of the first and second leads to insulate the
first and second leads from the casing when the smallest distance
between the casing and one of the first and second leads causes a
dielectric breakdown.
27. A magnetron for microwave ovens with a casing, comprising:
first and second leads; first and second insulators interposed
between and insulating the first and second leads from a bottom of
the casing, the first and second insulators having respective and
corresponding circular grooves and circular protrusions; a
connection part connected to the first and second leads to connect
a high voltage supply thereto; and a box covering the connection
part, wherein: the first and second leads are extended through and
are insulated from the casing and are supplied by a high voltage
supply such that a first voltage level is provided across the first
and second leads, the casing is maintained at a second voltage
level with respect to the first lead, and an insulating distance
for a dielectric breakdown between the casing and the connection
part is greater than a smallest distance between the casing and the
connection part to reduce a height of the box by reducing a height
of the first and/or second insulators.
28. A magnetron for microwave ovens including a positive polar
section forming a cavity resonator, a negative polar section
emitting thermions, and a yoke accommodating and supporting the
positive polar section, comprising: first and second leads
extending through a bottom of the yoke to be supplied with power by
a power source; a connection part connecting the first and second
leads with the power source; a box accommodating the connection
part therein; a first insulator fixedly supporting the negative
polar section, being positioned between the connection part and the
bottom of the yoke; and a second insulator interposed between the
connection part and the bottom of the yoke such that a dielectric
breakdown path is formed between the first and second insulators,
the first and second insulators are shaped such that the insulation
distance for a dielectric breakdown is greater than a distance
between the yoke and the connection part.
29. A magnetron for microwave ovens including a positive polar
section forming a cavity resonator, a negative polar section
emitting thermions, and a yoke accommodating and supporting the
positive polar section, comprising: first and second leads
extending through a bottom of the yoke to be supplied with power by
a power source; a connection part connecting the first and second
leads with the power source; a box accommodating the connection
part therein; a first insulator fixedly supporting the negative
polar section, being positioned between the connection part and the
bottom of the yoke; and a second insulator interposed between the
connection part and the bottom of the yoke such that by only
changing corresponding shapes of the first and second insulators,
respectively, an insulation distance for a dielectric breakdown is
changeable.
30. A magnetron for microwave ovens including a positive polar
section forming a cavity resonator, a negative polar section
emitting thermions, and a yoke accommodating and supporting the
positive polar section, comprising: first and second leads
extending through a bottom of the yoke to be supplied with power by
a power source; a connection part connecting the first and second
leads with the power source; a box accommodating the connection
part therein; and a fitting structure to lengthen a insulation
distance for a dielectric breakdown between the bottom of the yoke
and the connecting part by forming respective and corresponding
circular grooves and circular protrusions in first and second
insulators so that a height of the fitting structure is reducible
without causing the dielectric breakdown between the bottom of the
yoke and the connecting part.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of Korean Application
No. 2002-58413, filed Sep. 26, 2002, in the Korean Intellectual
Property Office, the disclosure of which is incorporated herein by
reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates generally to a magnetron for
microwave ovens, and more particularly, to a magnetron for
microwave ovens, which is provided with a filter box having a
reduced height.
[0004] 2. Description of the Related Art
[0005] In general, magnetrons are widely used to generate
microwaves in home appliances, such as in microwave ovens, as well
as in industrial applications, such as in high-frequency heating
apparatuses, in particle accelerators and in radars.
[0006] The general construction of such a magnetron is described
with reference to FIG. 1.
[0007] As shown in FIG. 1, in a magnetron 100, a plurality of vanes
102 that comprise a positive polar section together with a positive
polar cylinder 101 are radially arranged at regular intervals in
the positive polar cylinder 101 to form a cavity resonator, and an
antenna 103 is connected to one of the vanes 102 to induce
microwaves to an outside of the magnetron 100. Further, a filament
106 having a coil spring form is disposed along a central axis of
the positive polar cylinder 101, and an activating space 107 is
provided between radially inside ends of the plurality of vanes 102
and the filament 106. An upper shield 108 and a lower shield 109
are attached to a top and a bottom of the filament 106,
respectively. A center lead 110 is fixedly welded to a bottom of
the upper shield 108 while passing through a through hole of the
lower shield 109 and the filament 106. A side lead 111 is welded to
a bottom of the lower shield 109. The center lead 110 and the side
lead 111 are electrically connected to first and second terminals
104a and 104b, respectively, and the first and second terminals
104a and 104b, respectively, being connected to an external power
source (not shown). Thus, in the magnetron is formed an
electrically closed circuit in which the first terminal 104a, the
center lead 110, the upper shield 108, the filament 106, the lower
shield 109, the side lead 111 and the second terminal 104b are
electrically connected to each other in sequence. Other parts of
the magnetron 100 except for parts comprising the electrically
closed circuit are grounded. First ends of first and second choke
coils 105a and 105b are electrically connected to the terminals
104a and 104b, respectively, while second ends of the first and
second choke coils 105a and 105b are electrically connected to
respective terminals of a capacitor (not shown), which is mounted
on a side wall of a filter box 113 accommodating first ends of the
center and the side leads 110 and 111, respectively, and the first
and second terminals 104a and 104b or the first and second choke
coils 105a and 105b. The filter box 113 is made of a metallic
material to eliminate noise components irradiated through the
center and side leads 110 and 111, and is grounded. Further, an
upper permanent magnet 112a and a lower permanent magnet 112b are
provided to apply magnetic flux to the activating space 107 with
opposite magnetic poles of the upper and lower permanent magnets
112a and 112b facing each other. The positive polar section and the
permanent magnets 112a and 112b are accommodated in and supported
by a yoke 117. An upper pole piece 114a and a lower pole piece 114b
are provided to induce rotating magnetic flux generated by the
permanent magnets 112a and 112b into the activating space 107. An
upper shield cup 115a and a lower shield cup 115b are tightly
welded to the top of the upper pole piece 114a and the bottom of
the lower pole piece 114b, respectively.
[0008] An insulating ceramic 116 is tightly and fixedly welded to a
bottom of the lower shield cup 115b not only to seal an interior of
the positive polar cylinder 101 in a vacuum state but also to
prevent a dielectric breakdown phenomenon caused by a great
potential difference between a bottom of the yoke 117 and the first
and second terminals 104a and 104b or the first and second choke
coils 105a and 105b. The center lead 110 and the side lead 111 are
extended through holes formed in the insulating ceramic 116 to pass
through the bottom of the yoke 117, and are connected to the first
and second terminals 104a and 104b, respectively.
[0009] As shown in FIG. 2, when the magnetron 100 having the
above-described construction is employed in a microwave oven 200,
the magnetron 100 is disposed in a machine room 202 of the
microwave oven 200 and irradiates microwaves into a cooking cavity
201 of the microwave oven 200. Parts including a high voltage
transformer 204, a high voltage condenser (not shown) and a fan
motor (not shown) are arranged under the magnetron 100. The
insulating ceramic 116 is maintained to have a thickness of 16 mm
or more so that a secure insulation distance is maintained between
the bottom of the yoke 117 including the grounded lower shield cup
115b and the first and second terminals 104a and 104b or the first
and second choke coils 105a and 105b so as to improve the
efficiency of the magnetron 100 and to prevent harming the user.
Further, a spaced distance of 15.5 mm or more must be maintained
between the first and second terminals 104a and 104b or the first
and second choke coils 105a and 105b and a bottom of the filter box
113 accommodating the first and second terminals 104a and 104b or
the first and second choke coils 105a and 105b. Furthermore, a
diameter of each of the first and second choke coils 105a and 105b
must be taken into account. Accordingly, an entire height of the
filter box 113 generally is about 43 mm or more. Further, a
vibration and a noise may be generated between the filter box 113,
which is magnetically connected to the upper and lower permanent
magnets 112a and 112b by a magnetic force, and an outside wall of
the machine room 202, so a certain distance "d" must be maintained
between the bottom of the filter box 113 and the outside wall of
the machine room 202 to prevent the vibration and the noise from
being generated therebetween.
[0010] To maintain the above-described insulation distance and the
certain distance "d", an entire length of a magnetron must be
increased and a width "D" of the machine room 202 must be widened
in proportion to increases in a length of the magnetron.
Accordingly, a ratio of a volume of the machine room 202 to a
volume of the microwave oven 200 must be greater than that of a
volume of the cooking cavity 201 to the volume of the microwave
oven 200. For this reason, the conventional microwave oven is
problematic in that a design of the microwave oven 200 is
significantly restricted. In particular, this problem is fatal to
small-sized microwave ovens having a cooking cavity of a small
volume.
SUMMARY OF THE INVENTION
[0011] Accordingly, it is an aspect of the present invention to
provide a microwave oven in which a height of a filter box is
relatively reduced, so an entire height of a magnetron can be
reduced, thus implementing a miniaturization of the magnetron.
[0012] Additional aspects and/or advantages of the present
invention will be set forth in part in the description which
follows and, in part, will be obvious from the description, or may
be learned by practice of the invention.
[0013] The above and/or other aspects are achieved by providing a
magnetron for microwave ovens, including a positive polar section
forming a cavity resonator, a negative polar section emitting
thermions, a yoke accommodating and supporting the positive polar
section, leads extended to an outside through a bottom of the yoke
to be supplied with power by an outside power source, a connection
part connecting the leads with the outside power source, a filter
box accommodating the connection part therein, a first insulator
fixedly supporting the negative polar section, being positioned
between the connection part and the bottom of the yoke, and having
a certain height to maintain an insulation distance between the
connection part and the bottom of the yoke, and a second insulator
interposed between the connection part and the bottom of the yoke
to form a relatively lengthened insulation distance.
[0014] A molded insulating plate may be attached to a bottom of the
filter box to reduce an insulation distance between the connection
part and the bottom of the filter box.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] The above and/or other aspects and advantages of the
invention will be more clearly understood from the following
detailed description taken in conjunction with the accompanying
drawings, in which:
[0016] FIG. 1 is a longitudinal sectional view of a conventional
magnetron;
[0017] FIG. 2 is a longitudinal sectional view of a conventional
microwave oven;
[0018] FIG. 3 is a longitudinal sectional view of a magnetron in
accordance with an embodiment of the present invention;
[0019] FIG. 4 is a perspective view showing the first and second
insulators of FIG. 3; and
[0020] FIG. 5 is an enlarged sectional view of area A of FIG.
3.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0021] Reference will now be made in detail to the present
preferred embodiments of the present invention, examples of which
are illustrated in the accompanying drawings, wherein like
reference numerals refer to like elements throughout. The
embodiments are described below in order to explain the present
invention by referring to the figures.
[0022] FIG. 3 is a longitudinal sectional view of a magnetron in
accordance with an embodiment of the present invention. FIG. 4 is a
perspective view showing the first and second insulators of FIG. 3.
FIG. 5 is an enlarged sectional view of area A of FIG. 3.
[0023] As shown in FIG. 3, in a magnetron 300, a first insulator
301 of ceramic material having a height of 8 mm is welded to a
bottom of a grounded lower shield cup 303 not only to seal an
interior of a positive polar cylinder 302 in a vacuum state but
also to prevent a dielectric breakdown phenomenon caused by a
potential difference of about 4 KV between first and second
terminals 304a and 304b or between first and second choke coils
308a and 308b that are connected to a bottom of a yoke 311
including a grounded lower shield cup 303. A construction of the
first insulator 301 is illustrated in detail in FIG. 4. Two through
holes 401 are formed through the first insulator 301 around a
center axis of the first insulator 301 to pass center and side
leads 305 and 306 therethrough, and a circular groove 402 having a
certain depth is formed in the first insulator 301 around the
through holes 401. As shown in FIG. 3, a circular protrusion 501
formed on a second insulator 307 is fitted into the circular groove
402 of the first insulator 301. A construction of the second
insulator 307 is illustrated in detail in FIG. 4. In the second
insulator 307, a center opening 503 is formed at the center of a
disk 504 to pass the center and side leads 305 and 306
therethrough, and the circular protrusion 501 is circumferentially
extended around the center opening 503. A mounting protrusion 502
is circumferentially extended from an edge of the disk 504 and has
a diameter greater than that of the circular protrusion 501 in a
direction of the circumferentially extended circular protrusion
501. An upper end of the mounting protrusion 502 is fixedly
attached to the bottom of the yoke 311 including the positive polar
cylinder 302, as shown in FIG. 3, so that the circular protrusion
501 is fixedly fitted into the circular groove 402 of the first
insulator 301. Further, the disk 504 and the mounting protrusion
502 operate as insulators that insulate a lower side of the yoke
311 from the first and second terminals 304a and 304b and the first
and second choke coils 308a and 308b, as shown in FIG. 3.
[0024] With reference to FIG. 5, operations of the circular groove
402 of the first insulator 301 and operations of the circular
protrusion 501, disk 504 and mounting protrusion 502 of the second
insulator 307 are described below.
[0025] In a case where a dielectric is inserted into a gap between
two terminals having a certain potential difference, if the
potential difference between the two terminals is considerably
great, there occurs a dielectric breakdown phenomenon in which the
dielectric is broken down and a current flows between the two
terminals by a movement of ions. A degree to which a dielectric can
resist the dielectric breakdown phenomenon is referred to as a
dielectric strength. The dielectric strength is proportional to a
dielectric constant. The dielectric constant of air is about 1, and
air has a smallest dielectric constant of dielectrics. The
dielectric breakdown generally occurs at a position where an
electrical insulation distance is relatively short and a potential
difference is relatively great. In the magnetron 300, the
dielectric breakdown occurs between the bottom of the yoke 311 and
a connection part (including the first and second terminals 304a
and 304b and the first and second choke coils 308a and 308b) and
between a side and/or a bottom of the filter box 309 and the
connection part. In this case, if a pointed portion exists, an
electric field is concentrated on the pointed portion, thus causing
the dielectric breakdown to easily occur.
[0026] In general, air, which is a dielectric having a dielectric
constant of 1, is inserted into spaces between ground points
(including the bottom of the yoke 311 and the filter box 309) and
the connection part (including the first and second terminals 304a
and 304b and the first and second choke 308a and 308b coils). A
secure insulation distance that can prevent dielectric breakdown in
the air can be presumed to be about 16 mm. If a dielectric "A"
having a relatively high dielectric strength is positioned in a
space constituting an insulation distance, the insulation distance
is not a straight distance but a distance that is lengthened around
the dielectric "A" through a space occupied by the air. The reason
for this is that the dielectric breakdown cannot easily occur in
the dielectric "A" having the relatively high dielectric strength
but can occur in the air having a relatively small dielectric
strength and, in this case, the insulation distance and the
dielectric strength can be mathematically calculated.
[0027] Further, in FIG. 5, an insulation distance in a construction
of FIG. 3 is illustrated in detail.
[0028] An insulation distance between the bottom of the yoke 311
and the connection part is shown in FIG. 5. That is, an insulation
distance between the lower shield cup 303 having a ground point
closest to the first and second terminals 304a and 304b or the
first and second choke coils 308a and 308b and the first and second
terminals 304a and 304b or the first and second choke coils 308a
and 308b, is lengthened by a fitting structure in which the
circular protrusion 501 of the second insulator 307 is fitted into
the circular groove 402 of the first insulator 301. A lengthened
insulation distance "l" is indicated by an arrow line in FIG. 5.
Since the lengthened insulation distance "l" may be maintained to
be about 16 mm so as to prevent the dielectric breakdown, a depth
of the circular groove 402 and a height of the circular protrusion
501 may be so designed such that the lengthened insulation distance
"l" is maintained to be about 16 mm. Although in this embodiment,
the circular groove 402 is shown as a single circular groove 402
and the circular protrusion 501 is shown as a single circular
protrusion 501 corresponding to the single circular groove 402, a
plurality of circular grooves and a plurality of circular
protrusions corresponding to the circular grooves are formable in
the first and second insulators 301 and 307, respectively, so as to
further reduce a height of the first insulator 301.
[0029] Further, as shown in FIG. 3, to reduce a spaced distance
between the first and second terminals 304a and 304b or the first
and second choke coils 308a and 308b and the bottom of the filter
box 309, that is, an insulation distance therebetween, a molded
insulating plate 310 is attached to the bottom of the filter box
309. Further, the first and second terminals 304a and 304b and the
first and second choke coils 308a and 308b are maintained at a high
temperature ranging from about 200.degree. C. to about 300.degree.
C., so that the molded insulating plate 310 may be made of material
having a high thermal resistance to resist the high
temperature.
[0030] A height of the filter box 309 of the magnetron 300
constructed in accordance with the embodiment of the present
invention is reduced to about 23 mm.
[0031] As apparent from the above description, a magnetron, in
which a filter box thereof occupying about 40% of a height of the
magnetron is significantly reduced in height, so a miniaturization
of the magnetron can be implemented and a design of a product
including the magnetron, such as a microwave oven, can be carried
out, thus allowing an appearance of a product to be variously
designed.
[0032] For example, protrusions may be formed in the first
insulator and a circular groove may be formed in the second
insulator. That is, although a few preferred embodiments of the
present invention have been shown and described, it would be
appreciated by those skilled in the art that changes may be made in
these embodiments without departing from the principles and spirit
of the invention, the scope of which is defined in the claims and
their equivalents.
* * * * *